Thermoplastic fire-retardant, highpolymer, epoxide resin composition



United States Patent 3,277,048 THERMOPLASTIC FIRE-RETARDANT, HIGH-POLYMER, EPOXIDE RESIN COMPOSITION Lawrence F. Sonnabend, Midland,Mich., assignor to The Dow Chemical Company, Midland,.Mich., acorporation of Delaware No Drawing. Filed Jan. 16, 1961, Ser. No. 82,711

8 Claims. (Cl. 260-47) The invention relates to an improved resin whichemploys an epoxide or oxi-rane-containing compound in the preparationthereof. It more particularly refers to such resin which possessessubstantially all the desirable properties for practical purposes whichare normally associated with the class of resins known a epoxy resinsbut which is thermoplastic, which can be molded by thermoplastic moldingtechniques, and which has improved fire-retardant properties, and to themethod of making such resin.

The resin of the invention employs a diepoxide, i.e., (1) a compoundcontaining substantially two oxirane groups per molecule and (2) aphenolic compound, at least one of which reactants contains halogenatoms attached directly to carbon atoms of an aromatic ring. The termoxirane denotes a structure containing the ether linkage wherein oxygenis bonded to two carbon atoms to complete a ring. The halogen may be anyof the four elements so classed. However, fluorine is considered,generally, insufliciently effective as a fire-retardant substituent inthe invention, and iodine, on the other hand, is considered, generally,insufficiently stable, in the practice of the invention. The recommendedhalogens, therefore, in a practical sense, for use in the invention arebromine and chlorine.

Known epoxy resins, in general, are prepared by (l) reacting an epoxide,e.g., epichlorohydrin, with a dior polyhydric phenol or alcohol, e.g.,4,4'-isopropylidenediphenol, usually referred to by its trivial name ofbisphenol A, in the presence of an epoxidizing agent, e.g., NaOH, in amolar excess over the hydroxyl groups or (2) the epoxidation of adiolefin by an oxidizing agent, e.g., epoxidation of butadiene byperacetic acid.

The product, made by either of the above methods, is an epoxy resinintermediate or uncured epoxy resin. Dependent upon the molar excess ofepoxide over the alcohol or phenol, the resin is either a viscous liquidor an extremely brittle low-melting solid, either of which must besubsequently cured by admixture therewith of a hardening agent, usuallycomprising an amine, an aminated polyoxyalkalene glycol, a carboxylicacid, a carboxylic acid 'anhydride, a quaternary ammonium salt, or aboron trifluoride-amine complex, and curing at a temperature which isusually somewhat above room temperature for an appreciable number ofhours. The epoxy resin is thereby converted to a thermosetting resin.

Known epoxy intermediates have little direct use in the uncured statewhere strength properties are required.

Their principal use is an intermediate resin which is admixed with ahardening agent and subsequently cured, as aforesaid. Curing of suchepoxy intermediates entails a number of disadvantages among which aregreater inconvenience and increased production and equipment costs. Afurther undesirable condition accompanying the use of such widely usedhardening agents as amines is their inherent toxicity which isdetrimental to the health Patented Oct. 4, 1966 nor agent. It has a highmolecular weight of not less than about 30,000 and usually between50,000 and 70,000. It has excellent physical properties which make itparticularly suitable for a large number of uses. Among such physicalproperties are high tensile strength, percent elongation, modulus,flexural strength, impact resistance, dielectric, and electricalproperties. It is long-wearing and possesses high abrasion resistance.Long exposure to moisture, chemicals, sun, and heat at temperaturesbelow its softening point (subsequently described) have shown it toresist cracking, checking, flaking, or softening. It has a softeningtemperature of not less than about C. and usually not less than C. asdetermined by the Deflection Temperature of Plastics Under Load,A.S.T.M. Test No. D 64856. It is particularly adapted to injectionmolding whereas conventional thermosetting epoxy resins cannot beemployed for injection molding. It is fireretardant and, when preparedaccording to the preferred embodiment of the invention, is selfextinguishing as defined in the Test for Flammability of Rigid Plastics,A.S.T.M. Test No. D 635-56T.

The moldable or deformable composition of the invention is a highmolecular weight composition which consists essentially of the reactionproduct formed by heating for at least 0.25 hour, at at least C., 1) adiepoxide ether prepared by reacting an epichlohydrin with an hydroxycompound selected from .the class consisting of dihydric alcohols,dihydric phenols and bisphenols, and halogenated dihydric alcohols,dihydric phenols and bisphenols (2) a bisphenolic compound selected fromthe class consisting of bisphenols and halogenated bisphenols, in amolar ratio which provides between 0.95 and 1.05 oxi-rane groups in saiddiepoxide per hydroxyl group in said bisphenol, and at least 1 of saiddiepoxides or bisphenols containing halogen atoms attached directly tocarbon atoms of the aromatic nucleus in an amount sufficient to providethe necessary percent of halogen in the com-. position to render saidcomposition self extinguishing as defined in A.S.T.M. Test No. D 635-56Tand (3) a tertiary amine catalyst in an amount sufiicient to provide atleast 0.02 percent amine nitrogen (calculated as NR where R is ahydrocarbon group consisting of at least 2 carbon atoms) by weight ofsaid composition. When bromine is the halogen, the final resin productmust consist of at least 10.5 percent by weight of bromine and whenchlorine is the halogen, the final product must consist of at least 19percent by weight of chlorine to be self extinguishing.

The tertiary amine employed may be alkyl, alkaryl, aralkyl, and aryl,the alkyl amines being preferred. It is also preferred that at least oneof the alkyl substituents contain at least 2 carbon atoms. Illustrativeof the amines employed are triethylamine and .the isomers of tripropyl,tributyl, triamyl, and trihexyl amine diethylpropyl amine, andcombinations and mixtures thereof wherein at least one alkyl groupcontains at least 2 carbon atoms. The trihexyl amine is especiallyeffective in the practice of the invention. Trialkyl amines, wherein thealkyl groups consist of more than 6 carbon atoms, although not generallyeconomically available, may be used in the practice of the invention.The amount of amine nitrogen required seldom exceeds 0.1 percent byweight of said composition, although greater amounts may be employedwith no apparent adverse ellects. For easy calculation, tertiary amineshaving 2 to 6 carbon atoms in each alkyl substituent are usuallyemployed in an amount between 0.1 and 2.0 percent by weight of theresulting composition. Analysis of the nitrogen content of the tertiaryamines, removed after the reaction, have shown that substantially allthe amines may be removed thereby showing the catalytic nature of theamine, rather than a curing agent in the reaction.

After said reaction period, the resulting product is cooled to producethe hard semi-rigid composition of the invention. It is a thermoplastic,fire retardant, flexible, high molecular weight polymer showingrelatively high tensile strength and percent elongation values and asoftening point above 90 C., as determined by A.S.T.M. Test D 648-56T.The heating period is best described as a reaction period rather than acure in its customary sense. The amine serves as a catalyst and not as across-linking reactant. When the lower alkyl tertiary amines areemployed, a substantial portion of the amine catalyst volatilizes awayduring the reaction period. When the higher alkyl tertiary amines, sayon the order of 5 or 6 carbon atoms or more are employed, a substantialportion of the unreacted amine catalyst remains in the final product. Noundesirable effects have been observed to exist due to the presence ofthe residual unreacted higher amine. It is recommended that the loweralkyl amines be largely removed while the resin is deformable sincetheir presence as a gas sometimes produces bubbles or voids in thefinished resin. It is not recommended that the reaction take place at atemperature greater than about 240 C., the temperature usually employedbeing between 190 and 220 C. A reaction period within this preferredtemperature of longer than 0.25 hour produces little change intheproduct and a period beyond 0.5 hour at these temperatures gives nonoticeable improvement. Tests conducted on three otherwise identicalresin compositions of the invention prepared at a reaction temperatureof about 215 C., one of which has been kept at the reaction temperaturefor 0.5 hour, another 1 hour, and still another for 24 hours, andsubsequently cooled, showed no significant measurable differences inphysical properties.

The compound while still deformable may be conveniently employed in alaminating, coating, impregnating, encapsulating, potting, or embeddingoperation; it may be extruded in the shape of tubes, bars, rods, or asstrands, the strands upon solidifying being suitable for weaving intofabric; it may be pressure molded or otherwise formed into any shape forwhich an appropriate mold or shaping equipment is obtainable. It isespecially useful for making resinous articles and materials which maybe subjected to flame or high temperature. It may be cast intoconvenient size shapes or into convenient strands, which upon beingcooled below the softening point are subse- 'quently broken into bits orparticles as by means of a suitable crusher or grinder, and the t-huspulverized or particulated resin subsequently employed as molding powderor granules according to conventional practice employing thermoplasticresins. If his desired to reshape an article made of the resin of theinvention, it may be reheated above its softening temperature andreshaped.

A particular advantage of the resin of the invention is the relativelyshortreaction period required to convert it to the useful finishedsemi-rigid material described above without additional treatment. Areaor space requirements, labor costs, and handling equipment needs arereduced to an unprecedented low level for a resin which possessesphysical strength properties comparable to thermosetting resins plusadded flame retardant and injection molding properties.

The composition of the invention may be prepared in mass, i.e., withoutthe use of a solvent, or a substantially inert liquid reaction mediummay be employed to provide a solvent system. The composition may beproduced either batchwise or by continuous operation.

According to the preferred batchwise mode of preparation, the epoxideand the phenolic compound are admixed in a reaction vessel provided withheat control and agitation means. A solvent is usually employed todecrease the viscosity but is not necessary, e.g., in small batchoperations. The vessel is preferably covered and equipped with a lead-inpipe, connected to a substantially inert gas source, usually nitrogen.The .epoxide ether and phenolic mixture is usually premixed by heatingto between about and C. and held at that temperature accomtherewith.After the amine is mixed into the reaction mixture, the temperature isthen raised to at least about C. and held at between 165 C. and 240 C.,pref-1 erably at between 190 and 230 C. for 1 hour. ,Longer times appearnot to be detrimental but also not to result in an improved product. Theresin thus formed may be then applied for laminating, impregnating, ortherlike, or it may be molded or otherwise formed into desired shapes asabove suggested. If a solvent is employed in the batch operation, it isrecommended that the resin, prior to cooling and preferably at anadvanced temperature of between 220 and 160 C., be subjected to avolatilizing step to remove the solvent. Upon cooling the resin to belowits softening temperature, a hard durable resinous coating or film, castarticle, or material to be particulated and used for compression orinjection molding, is thus produced.

In the preferred continuous mode of operation, which is generally moreetficient and convenient than the batchwise mode of making the resin ofthe invention, a suitable organic solvent, e.g., toluene, benzene,xylene, or a ketone, is usually fed into a pre mixing vessel providedwith stirrer, heat control means, suitable temperature-recordinginstruments, and flow control means for introducing reactants, andsolvent, all of which are usually located near the top of the vessel,and a controlled dischargemeans for. removing the premix, located at thebottom of the vessel. A solvent, similarly as in the batchwise mode ofoperation, is not necessary but has been found to facilitate stirringand transfer of the reaction mixture. The epoxide and the phenoliccompound, in amounts suflicient to provide substantially the equivalentnumber of each of the oxirane groups and phenolic hydroxyl groups, are,fed

into the vessel. The solvent is usually employed in an amount of about20 to 50 percent by weight of the total charge. The contentsare stirredand heated to a temperature at which the reaction mixture issubstantially homogeneous. When an appropriate solvent is employed, thistemperature is lower than is permissible in ,a no-solvent system. Thetemperature employed, therefore, is dependent in part upon the eflicacyand concentration of the solvent. The temperature is usually not overabout 100 C. This step is largely a mixing and preheating step and thetime isnot highly critical. The tertiary amine may be added directlyinto the premix. However, it is preferably admixed with the outgoingpremix.

The discharge from the mixing vessel leads either into an intermediatereaction vessel at between. about 85 and 115 C. and then into heatedtubes or directly into a separate reaction vessel, either of which isusually maintained at a temperature of between about 1:80 and 240 C. Theintermediate heating step is'not necessary,

and if preferred, the premixture may be subjected at once 15 minutes isusually ample. On the other hand, for

convenience, the reaction mixture may be allowed to remain in the heatedtubes or vessel for 8-10 or more hours. 'It is then led into a ventedvessel maintained at a temperature of between about 180 and 260 C(usually between about 225 and 240 C.) where the solvent is volatilizedoff when used, and the more volatile amines are also largely volatilizedoif. Thereafter the I resin may be drawn therefrom, while still aboveits softening temperature, into suitable molds, an extruder chamber,onto film-forming rollers, or onto a material to be coated,

impregnated, or the like, and the thus formed or spread resin allowed tocool. 'However, it is preferably drawn 01f through one or more orificesand subsequently cooled to form convenient shaped strands or the likefor use,

as such, or for subsequently chopping or crushing for use as moldinggranules.

The epoxide used in the preparationof the composition It is to be bornein mind, of course, that at least of F illvention, as aforesaid, is thediglycidyl ether of one of R or R must be halogenated and the thushalolf 9 lf q P r of such Phenol genated reactant employed insufl'icient proportion to prowherem bromme P 9 15 substltuted on theoarbpfl vide the required minimum percent by weight of halogen atoms ofthe Phfmohc i 3 epoxlde in the end product to impart the property ofself extindoes not contain halo-substituted phenolic ring-s, thenguishing thereto. It must further be home in mind that the plienoficcpmpound p Fonsist 9 3 dihydric phenol the molar ratio of epoxide tobisphenol must be within wherem bmmme or l subututed on the carbon theaforesaid ratio of between 0.95 to 1.05 and preferably atoms of thephenolic ring to PIOV-ldG the necessary brob t flan 1 mine or chlorinecontent in the end product. 10 Su 5 an y i The chemical action thoughtto take place wherein The flow shefit Set out below a 'f the diepoxideis a diglycidyl ether of a bisphenol may be U011 of a contlmlous mode ofmaking the composltlon represented by the following equation: of theinvent-ion. It is suggestive of but one mode and where R is the arylresidue of the phenolic compound is not intended .to define limits forcarrying out the and R is the aryl residue of the diglycidyl ether and ninvention. is about 60 or more. 7

R or R may be the same but usually only one is chlorinated orbrominated. In practice the phenolic compound is most often chlorinatedor brominated and the diglycidyl ether is a low molecular weightsubstantially pure diglycidyl ether of a bisphenol since such materialsare readily available. Mixture of Illustrative of R and R, the repeatingaryl groups Ewxide and 7 halogenated 1n the product represented 1n theabove equation, are Bisphenol the following: t

C1 C1 Mixing Pump CH i Feed Pump a J C1 l First Stage Br B1 Reactom.

CH3 Temp: 80-l20C Q- 1 H 5 3 Br 3 Br Br Br H 2 l-leated tubes, I Temp:l-2 l0C H r Br Br Exhaust duct. (30 to 50 mm of Hg) 6O i 7 E Vacuum Pump6 Volatilizer 3 for solvent and lower boiling Catalyst t-amine catalyst,I and Solvent 65 temp: l90-260C Recovery CH3 Means Orifice I Resinoutlet or Valve 6 ALI Cooled V r v Chopper for H making molding k V igranule outlet The following examples are illustrative of the practiceDissipationfactor at designated-cycles per. of the invention: 7 second:o o Example 1 10 o .0020

A mixture of 172.5 grams of the diglycidyl ether, 2,2- 5 do .0135bis[p-(2,3-epoxypropoxy)phenyl]propane and 183 grams 10 do .0240 of4,4'-isopropylidenebis(2,6-dich10ropl1en0l) were placed 5 X 107 "0373 ina reaction vessel of the type above described and heated g- P 3 1 t t at135 C. while being stirred. This mixture provided Hi fi f 6 gg empen: g196 substantially equal equivalents of oxirane and hydroxyl 10 o h th 1it h d of the e nation Light stability by Fade-O-meter color groups as 8Own on g 1 q change test. A.S.T.M. recommended above. 2.8 grams ofrlethy mine wer added Whlle practiceE42 5-; "hours" 100 stirring.Equal-amounts of the material were then poured M olecular weight asdescribed in Number I into three 200 milliliter iron crucibles. Thecrucibles were Average Molecular Weight, by Barman placed in an oven,raised to a temperature of 225 C. and Dimbbet, and Stross pages 191461000 held at between 220 and 225 C. for 1 hour and then re- Flammability1 test B63546 moved from the oven and allowed to cool to room tem-Self-extinguishing pelatul'ei The prloduct flprmed was a lclealrhght-ccillo g Laminated resin samples 05 thefilitlventior for use finthe thermop astic p0 ymer aving a mo ecuar weig to flammability testwere prepare as o orys: quares 0 gass 61,000. The product was groundthrough a hammer mill i g gfffiiffy 3 t ggi ggfi ffifigiif gg $233521.

n ,n I! o l O and then molded mto sheets of 0.125 inch thickness. Test if /g fi m lifi g of a specunens were Cut from the molded sheet. 7 etherof bisphenol A, tetrachloropisphenol A and triethyl- Too nnoonoonnoonnono on tho nnnonnon no nndo wono Bassinet; as t then subjected toa series of tests to show the more C. and a pressure of 780p.s.i.was.app1ied to the surface of the resin-impregnated glass clothfor at 0.5 hour to. produce 531mm P y propertles- The Propertlesascertamed y resin lalmnatedtlglass tilioth sgctioisi. tThaz 5sectitlilns gviere gtlhien remov 0 1110 n 0 W S S the tests are set out mTable I below svhclfiwgrg t l ien s ubjecte d l t thi flammability estdes ignat d 111 3. e TABLE I Property: I I a Epoxidepolymer Reference toTable I shows that the thermoplastic resin o Ultimate i e: test 3 5 ofthe invention has good elongation and modulus as Well 8300 as hightensile strength properties, high molecular weight, Ultimate elongationA.S.T.M. test D638- g g ssg insulatmg ProPgmes: and .5

58T percent 3.7 Tensile modulus (modulus of elasticity) To Show efiectof vafymg the molar and A S T M t 3638 s 4 3 105 thereby the equivalentsof oxirane groups to phenohc hy- 1 es xTf' X droxyls and also .of,varying the percent of amine cat- Impact Ieslstance at test alystpresent, the Examples 2 to 6 of the invention and 13256-56 of notch"comparative Runs A and B were made. The procedure Rockwell hardnessnumber M scale; 40 employed was substantially. the same as that ofExample test 53 1 above. The epoxide employed was the diglycidyl etherDielectric constant at designated cycles per of bisphenol A having anaverage epoxide equivalent second: weight of 172.4 except that ofExample 5 wherein the 10 micro-microfarads 3.73 average epoxideequivalent weight was 188. The bis-I 10 ....d0 3.71 phenol employed wastetrachlorobisphenol' A. The cat- 10 3.65 alyst was tri-n-butylamine.The equivalents of epoxide.

1-0 do 3.65 and phenolic hydroxyls and percent by weight of amine 5 l0do 3.37 employed, as well as outstanding characteristics of the A.S.T.M.test D15054T resin so made, are shown in Table 11 below.

TABLE II Catalyst 3 Q Percent Run Number Equivalents Equivalents Concen-Reaction Reaction Tensile Elonga- Epoxide 1 Phenolic OH 2 tration,Temp., C Time, 11:. Strength ation Percent Example 2 1. 0 1. 0 1. 0 2151 10 650 s. 5 Comparative Run .A 1. 0 0. 9 1. 0 215 1 Too hrittle totest Comparative Bun B 1. 0 1. 1 1. 0 215 1 Too brittle to test Example3. 1. 0 1. 035 1. 0 215 1 s, 550 6. Example 4 1. 0 0.96 1. 0 215 1 s,300 t Example 5--- 1. 0 1. 0 1. 0 215 1 7, 400 4. Example 6 1. 0 1. 0 0.4 215 4 3 7, i 5.

l The diglycidyl ether of bisphenol A. 3 Tetrachlorobisphenol A.Tri-n-butylamine, by weight.

I All resins made were sell extinguishing.

cit-m o 9 Reference to Table II shows that the best results are obtainedwhen equivalents of oxirane groups and phenolic in and impact testsidentified in Table I. The results are shown in Table III below.

TABLE 111 Impact Grams of Grams of Grams of Grams of Tensile Elongastrength Example diglycidyl tetrachlorotetrabromotriethylstrength tionin in foot N o. ether of bisphenol A, bisphenol A amine in p.s.i.percent pounds bisphenol A per inch of notch Ep'oxide equivalent weightwas 17 3179.

hydroxyl groups are employed, but that acceptable results are obtainedwhen the ratio of oxirane groups to phenolic hydroxyls varies from 0.96to 1.035. Examination of the resin samples indicate that the acceptablemolar ratio of oxirane to phenolic hydroxyl groups is from 0.95 to 1.05.However, as shown by comparative Runs A and B, when the molar ratio ofoxirane to hydroxyl groups is as low as 0.9 or as high as 1.1, theresulting resin is too brittle to be acceptable.

The moplastic resins, made according to the procedure employed in theexamples shown in Table H, were placed in an injection molding chamberconnected to a by A3 (about 0.0234 square inch cross-section) spiralmold. The resin was heated to 450 F. and a measured pressure applied toforce the resin into the spiral mold a distance of about 22 inches. Theprocedure was repeated using a second spiral mold of the same dimensionsas the first, but heating the resin to 475 F. The same pressure forcedthe resin into the mold a distance of about 26 inches. The procedure wasagain repeated using a third mold of the same type, but heating theresin to 500 F. The same pressure forced the resin into the mold adistance of 32 inches. The molded spirals were cooled, removed from themolds and examined. They were strong, flexible and uniform, had a clearsurface and were transparent, thereby evincing the suitability of theresin of the invention for injection molding.

To show the result of employing various mixtures of tetrabromobisphenolA and tetrachlorobisphenol A with the diglycidyl ether of bisphenol A,examples 7 to were run. In these examples, the Weights oftetrabromobisphenol A, tetrachlorobisphenol A, and the diglycidyl ether,in the amounts shown in Table II, were mixed at a temperature of about125 C. in a reaction kettle. The mixture so made was then cooled toabout 110 C. and

1.1 grams of triethylamine admixed therewith. The mix- Reference toTable III shows that a resin, having good physical properties, resultswhen employing mixed halobisphenols with a diglycidyl ether in thepractice of the invention. All the resin samples made contained an amplenumber of halogens attached to aromatic nuclei to insure their beingself extinguishing.

It is, therefore, shown that mixtures of chlorinated and brominatedbisphenols may be employed with a diglycidyl ether of a polyhydricphenol so long as the resulting resin possesses suflicient total halogencontent to be self extinguishing. For purposes of easy reference, TableIV is set forth showing the lowest percents of bromine and chlorine, inmixed halogenated bisphenols, necessary in the resin, based on theweight of the resin, to insure that it be self extinguishing.

TABLE IV Percent Bromine Percent Chlorine TABLE V Grams of Im actlow-chlorme Grams of Tensile Elongain ihot Example No. diglycidyltetrachloro- Grams of amme catalyst Strength tion in pounds ether ofblS- bisphenol A in p.s.i. percent per inch phenol A of notch 69 73. 22.15 tri-n-butylamine 10, 500 11. 9 1. 84 G9 73. 2 1.65tri-n-propylamine-.. 10, 200 7. 4 2. 00 69 73. 2 2.6 tn-iso-amylamine10, 400 7. 8 1. 4

1 1 Reference to Table V shows that the physical properties are improvedby employing a purified diglycidyl ether. The table also shows thatvarious tertiary amines may be employed to produce the high strengthself extinguishing thermoplastic resin of the invention.

Having described the invention, What is claimed and desired to beprotected by Letters Patent is:

1. A moldable thermoplastic self-extinguishing solid resin composition,having a tensile strength of at least about 7000 pounds per square inch,a percent elongation of at least about 3.5, a tensile modulus of atleast about 4.0 10 pounds per square inch, an impact resistance of atleast about 1.5 foot pounds per inch of notch, a Rockwell hardness of atleast about 50, a dielectric constant at 10.5 cycles per second of .atleast about 3.5

micro-microfarads, a heat distortion temperature of at least about 190F., and a molecular weight of at least about 30,000, which consistsessentially of the reaction product of (1) a diglycidyl ether having anaverage of about two terminal oxirane groups per molecule, prepared byreacting epichlorohydrin with an hydroxy compound selected from theclass consisting of 4,4'-isoalkylidenebis(2,6-dibromophenol),4,4-isoalkylidenebis 2,6-dichloro phenol) 4,4-methylenebis2,6-dibromophenol) 4,4-isoalkylidenebis (bromophenol .4,4'-methylenebis(2,6-dichlorophenol) in a ratio ofbetween 0.95 and 1.05 moles of thediepoxide ether per mole of the bisphenolic compound, at least one ofthe diepoxide ether and bisphenolic reactants containing halogensubstituents selected from the class consisting of bromine and chlorineattached directly to carbon atoms of the aromatic nuclei, such halogensubstituent being present in an amount suflicient to provide at least10.5 percent of bromine, when bromine is the halogen, and at least 19.0percent of chlorine, when chlorine is the halogen, based on the weightof said composition, in-the presence of (3) a tertiary amine catalyst,in an amount suflicient to provide at least 0.02 percent nitrogen, byweight of said composition, added as NR wherein each R is an alkylsubstituent containing between two and six carbon atoms.

2. The method of making a thermoplastic self-extinguishing flexiblesolid resin composition of high molecular weight and high tensilestrength which consists essentially of the steps of admixing an alkyltertiary amine catalyst having from 2 to 6 carbon atoms in each alkylsubstituent in an amount sufiicient to provide at least 0.02 percentnitrogen by weight of said composition, with a mixture of a diglycidylether of a dihydric phenol and a halogenated polyhydric phenol, thehalogen substituent thereof being selected from the class .consisting ofbromine and chlorine in an amount suflicient to provide a total of atleast 10.5 percent bromine, when bromine is said substituent, and atotal of at least 19.0 percent chlorine, when chlorine is saidsubstituent, based on the weight of said composition, in a ratio ofbetween 0.95 and 1.05 moles of said epoxide ether per mole of saidphenol, subjecting the mixture thus made to a tem perature of betweenand C. for at least about 0.25 hour, then subjecting the thus heatedmixture to a temperature of between about and 240 C. for an additionalperiod of at least about 0.5 hour, and thereafter passing the thusheated reaction mixture into a vented vessel which is maintained at atemperature of between about and 260 C. and drawing off from the bottomof said vented vessel the thermoplastic resinous product.

3. The method according to claim 2 wherein the.

thermoplastic resinous product is drawn off through a narrowhorizontally elongated die to form a film of said product and coolingthe film so made to below 90 C.

4. The method according to claim 21whereinv the thermoplastic resinousproduct is drawn off through an orifice to form strands of said productand cooling the strands so formed to below 90 C. i 5. The methodaccording to claim 4 wherein said strands, subsequent to cooling, areparticulated to form granules suitable for use in film forming,injection moldmg, compression molding, and extruding.

6. The composition of claim 1 wherein the bisphenolic compound is4,4-isopropylidenebis(2,6-dibromophenol).

7. The composition of claim 1 wherein the bisphenolic 1 compound is4,4'-isopropylidenebis(2,6-dichlorophenol).

8. The composition of claim 1 wherein the diepoxide ether is thediglycidyl ether of 4,4-isopropylidenediphenol.

References Cited by the Examiner UNITED STATES PATENTS 2,451,986 10/1948 Slaughter 18-55 2,467,171 4/ 1949 Werner et al 260348 2,602,075 7/1952 Carpenter et al. 26047 2,837,497 6/1958 Delmonte 26047 3,004,95110/ 1961 Dazzi 26047 3,016,362 1/1962 Wismer 26047 3,074,974 1/ 1963Gebura 26047 OTHER REFERENCES Lee et al., Epoxy Resins pages 35-41relied on, July 1957.

Hackhs Chemical Dictionary, 3rd Ed., 1944, published by McGraw-Hill BookCo. (page 310 relied on).

Zaehringer, Solid Propellant Rockets, 1958; published by American Rocket00., Box 1112, Wyandotte, Mich. (pages 209, 210, 211, 212, 213, 214 and215 relied on).

WILLIAM H. SHORT, Primary Examiner.

HAROLD N. BURSTEIN, Examiner.

T. D. KERWIN, A. L. LIBERMAN,

Assistant Examiners.

1. A MOLDABLE THERMOPLASTIC SELF-EXTINGUISHING SOLID RESIN COMPOSITION,HAVING A TENSILE STRENGTH OF AT LEAST ABOUT 7000 POUNDS PER SQUARE INCH,A PERCENT ELONGATION OF AT LEAST ABOUT 3.5, A TENSILE MODULUS OF ATLEAST ABOUT 4.0X10** POUNDS PER SQUARE INCH, AN IMPACR RESISTANCE OF ATLEAST ABOUT 1.5 FOOT POUNDS PER INCH OF NOTCH, A ROCKWELL HARDNESS OF ATLEAST ABOUT 50, A DIELECTRIC CONSTANT AT 10.5 CYCLES POUND SECOND OF ATLEAST ABOUT 3.5 MICRO-MICROFARADS, A HEAT DISTORATION TEMPERATURE OF ATLEAST ABOUT 190*F., AND A MOLECULAR WEIGHT OF AT LEAST ABOUT 30,000WHICH CONSISTS ESSENTIALLY OF THE REACTION PRODUCT OF (1) A DEGLYCIDYLETHER HAVING AN AVERAGE OF ABOUT TWO TERMINAL OXIRANE GROUP PERMOLECULE, PREPARED BY REACTING EPICHLOROHYDRIN WITH AN HYDROXY COMPOUNDSELECTED FROM THE CLASS CONSISTING OF4,4''-ISOALKYLIDENEBIS(2,6-DIBROMOPHENOL),4,4''-ISOALKYLIDENENEBIS(2,6-DICHLOROPHENOL),4,4''-METHYLENEBIS(2,6-DIBROMOPHENOL),4,4''-ISOALKYLIDENEBIS(BROMOPHENOL),4,4''-METHYLENEBIS(2,6-DICHLOROPHENOL),4,4''-METHYLENE-BIS(2,6-DIBROMOPHENOL), 4,4''-METHYLENEBISDIPHENOL, AND4,4''-ISOALKYLIDENEDIPHENOL AND (2) A BISPHENOLIC COMPOUND SELECTED FROMTHE CLASS CONSISTING OF 4,4''-ISOLALKYLIDENEBIS(2,6-DIBROMOPHENOL),4,4''-ISOALKYLIDENE(2,6=DICHLOROPHENOL),4,4''-ISOALKYLINENEBIS(CHLOROPHENOL),4,4''-ISOALKYLIDENEBIS(BROMPHENOL),4,4''-METHYLENEBIS(2,6-DICHLOROPHENOL),4,4''-METHYLENEBIS(2,6-DICHLOROPHENOL), 4,4''-METHYLENEBISDIPHENOL, AND4,4''-ISOALKYLIDENEDIPHENOL, IN THE RATIO OF BETWEEN 0.95 AND 1.05 MOLESOF THE DIEPOXIDE ETHER PER MOLE OF THE BISPHENOLIC COMPOUND, AT LEASTONE OF THE DIEPOXIDE ETHER AND BISPHENOLIC REACTANTS CONTAINING HALOGENSUBSTITUENTS SELECTED FROM THE CLASS CONSISTING OF BROMINE AND CHLORINEATTACHED DIRECTLY TO CARBON ATOMS OF THE AROMATIC NUCLEI, SUCH HALOGENSUBSITUENT BEING PRESENT IN AN AMOUNT SUFFICIENT TO PROVIDE AT LEAST10.5 PERCENT OF BROMINE, WHEN BROMINE IS THE HALOGEN, AND AT LEAST 19.0PERCENT OF CHLORINE, WHEN CHLORINE IS THE HALOGEN, BASED ON THE WEIGHTOF SAID COMPOSITION, IN THE PRESENCE OF (3) A TERTIARY AMINE CATALYST,IN AN AMOUNT SUFFICIENT TO PROVIDE AT LEAST 0.02 PERCENT NITROGEN, BUTWEIGHT OF SAID COMPOSITION, ADDED AS NR3 WHEREIN EACH R IS AN ALKYLSUBSTITUENT CONTAINING BETWEEN TWO AND SIX CARBON ATOMS ATOMS.